New fluorescent 3H-imidazo[4,5-e][2,1]benzoxazoles: synthesis, spectroscopic characterization, and antibacterial activity

作者：Rezazadeh Mitra^*; Pordel Mehdi; Davoodnia Abolghasem; Saberi Sattar

来源：Chemistry of Heterocyclic Compounds, 2015, 51(10): 918-922.

DOI：10.1007/s10593-015-1796-0

• 3H-imidazo[4,5-e][2,1]benzoxazole
• 5H-imidazo[4,5-f][2,1,3]benzoxadiazole 3-oxide
• emission and absorption spectra
• fluorescence
• NOESY

The new fluorophores of the 3H-imidazo[4,5-e][2,1]benzoxazoles series were synthesized by the regioselective nitration of 3-alkyl-8-phenyl-3H-imidazo[4,5-e][2,1]benzoxazoles. The latter compounds were obtained from the reaction of 1-alkyl-5-nitro-1H-benzimidazoles with benzyl cyanide in basic MeOH solution. The structures of synthesized compounds were established using spectral (UV-vis, IR, H-1 NMR, C-13 NMR, and NOESY) and analytical data. Furthermore, it was found that these fluorophores underwent thermal rearrangement to new 5H-imidazo[4,5-f][2,1,3]benzoxadiazole 3-oxides in AcOH in moderate yields. The fluorescence properties and antibacterial activities of new compounds against Gram-positive and Gram-negative bacterial species were also studied.

• 出版日期2015-10